Connector for flat cable

ABSTRACT

A flat cable having laterally spaced ribbon conductors embedded in its insulation is inserted into a plastic block containing a rotatable cylinder. The cylinder has a diametrically oriented slot for the reception of the inserted end of the flat cable. An annular space circumscribes the cylinder and a number of serrated contacts extend into the annular space so that when the cylinder is rotated the teeth on the contacts peel the insulation from the cable to establish electrical engagement with the ribbon conductors.

United States Patent Inventor Ottomar H. Vetter Minneapolis. Minn.

App]. No. 855,695

Filed Sept. 5. 1969 Patented Sept. 14, 1971 Assignee United-Carr Incorporated Boston, Mass.

CONNECTOR FOR FLAT CABLE 7 Claims, 4 Drawing Figs.

[1.8. CI 339/99 R Int. Cl H01r 9/08 Field of Search 339/94, 97-99 [56] References Cited UNITED STATES PATENTS 3,365,695 1/1968 Harvey et al 339/99 3,477,059 11/1969 Cole 339/99 Primary Examiner-Joseph H. McGlynn Altorney- Dugger, Peterson, Johnson & Westman ABSTRACT: A flat cable having laterally spaced ribbon conductors embedded in its insulation is inserted into a plastic block containing a rotatable cylinder. The cylinder has a diametrically oriented slot for the reception of the inserted end of the flat cable. An annular space circumscribes the cylinder and a number of serrated contacts extend into the annular space so that when the cylinder is rotated the teeth on the contacts peel the insulation from the cable to establish electrical engagement with the ribbon conductors.

CONNECTOR FOR FLAT CABLE BACKGROUND OF THE INVENTION This invention relates generally to electrical connectors, and pertains more particularly to a connector to which can be attached a flat cable having a number of laterally spaced ribbon conductors embedded in its insulation.

SUMMARY OF THE INVENTION One object of the invention is to provide a connector that will accept one end of a flat cable having ribbon conductors contained in its insulation, sufficient insulation being automatically scraped or peeled off during the attaching procedure. More specifically, the invention has for an aim the insertion of one end of an unbared flat cable and by rotating a cylinder contained in the connector the insulation is removed from the cable adjacent the embedded ribbon conductors.

The invention has for a further object the provision of a connector that will securely retain the inserted end of the flat cable once the cylinder forming part of the connector has been rotated so as to establish the desired electrical connection between serrated contacts permanently held by the connector.

Still another object is to effect the facile release of the cable when desired.

Another object of the invention is to provide seals so that the connector is impervious to the entrance of moisture into the connector and thus precludes contamination of the electrical connection that has been established within the connector.

Briefly, a block of dielectric material has an entrance slot via which one end of a flat cable is inserted, there being a rotatable cylinder provided with a diametrically disposed slot that is first rotated into alignment with the entrance slot. By reason of an annular space circumscribing the cylinder, the space being substantially equal to the thickness of the flat cable, the inserted cable end can be pulled into the connector past a number of serrated contacts which scrape off sufficient insulation so that the desired electrical contact between the ribbon conductors of the flat cable and the serrated contacts can be made. Seals prevent the entrance of moisture and airborne contaminants which might adversely affect the electrical connection within the connector. By virtue of the twisting or rotation of the cylinder, the flat cable is securely retained so that it cannot be accidentally detached from the connector, yet allowing intentional detachment if circumstances so dictate.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a connector exemplifying the present invention with one end of a flat cable secured therein, the cable being only fragmentarily depicted;

FIG. 2 is a sectional view taken in the direction of line 22 of FIG. 1;

FIG. 3 is a sectional view taken in the direction of line 3--3 of FIG. 2; and

FIG. 4 is a sectional view corresponding to FIG. 3 but illustrating the connector prior to rotation of the slotted cylinder through which the flat cable has been inserted.

DESCRIPTION OF THE PREFERRED EMBODIMENT Inasmuch as my invention is intended to be used for connecting a flat cable, a typically constructed cable designated generally by the reference numeral has been illustrated. The covering for the cable can comprise Mylar (polyethylene terephthalate) insulation 12 or other relatively soft dielectric material, such as rubber, in which is embedded a plurality of laterally spaced ribbon conductors 14.

The connector embodying my invention has been indicated generally by the reference numeral 16 and includes a block 18 of suitable relatively hard dielectric material, such as phenolic plastic. While the block 16 has been shown as of unitary construction, it will be understood that it may be fabricated in sections and suitable cement employed to adhesively bond such pieces together. As best seen in FIG. I, the block 18 is formed with a pair of integral mounting ears 20 having mounting apertures 22. Also, it will be perceived that the block 18 is formed with an entrance slot 24 via which one end of the flat cable [0 can be inserted and an internal cavity or bore 25 into which the slot 24 leads.

Within the bore 25 of the block 18 is contained a cylinder 26 having bearing portions 28 that permit the rotation of the cylinder 26. In order to effect the desired rotation of the cylinder, the cylinder is formed at one end with a hexagonal head 30 and at the opposite end a nut 32 is threadedly applied. A washer 34 at each end allows easy rotation of the cylinder 26 when anchoring the cable 10. Still further, it is to be observed that the cylinder 26 has a slot 36 diametrically disposed therein. The slot 36 is registrable with the entrance slot 24, as can be seen in FIG. 4.

An annular clearance or space 38 is provided between the cylinder 26 and the interior of the block 18. The diameter of the cylinder 26 is sufficiently small to provide this space 38 and the space is intended to accommodate therein the thickness of the flat cable 10. In other words the cross section of the cylinder 26 does not fully occupy the bore 25.

As can be seen in FIGS. 2, 3 and 4, a number of contact elements 40, which include in each instance a serrated strip portion 41 having teeth 42 thereon, are held in the dielectric material constituting the block 18, the various strip portions extending tangentially into the annular space 38 in a quadrant relationship with the entrance slot 24. It will be understood that the number of serrated contact elements 40 corresponds to the number of ribbon conductors 14 contained in the particular flat cable 10 that is to be connected and that the strip portions 41 and teeth 42 radially occupy a portion of the space 38 generally equal to the thickness of the insulation 12 overlying the conductors 14. The contact elements 40 may be considered to be of the solderless crimp-on type, and therefore have integral therewith a barrel or sleeve 44. Of course, the particular mode of attachment of the contact elements 40 to conventional conductors 45 having exposed wire ends 46 covered with insulation 48 is unimportant to a practicing of the instant invention.

The bore 25 of the block 18 is formed with a pair of laterally directed grooves 50, 52 that are angularly spaced from each other as is evident from FIGS. 3 and 4. The groove contains an elastomeric seal 54 that projects radially into the annular space 38 and abuts against the cylinder 26, preferably in a slightly compressed state. On the other hand, the groove 52 contains a similar elongated seal 56 that extends toward the cylinder 26 but terminates in a spaced relationship therewith so as to permit passage of the inserted end portion of the flat cable 10. Still further, the cylinder 26 contains a groove 58 for the accommodation therein of a seal 60 that projects outwardly toward the block 18 but terminates in a spaced relationship therewith, here again allowing for the accommodation of the inserted cable portion.

As far as the procedure for establishing electrical contact of the cable 10 within the connector 16 is concerned, it will be helpful to first refer to FIG. 4. FIG. 4 shows the cylinder 26 in a rotative position such that its slot 36 is in alignment or registry with the entrance slot 24 formed in the dielectric block 18. When such alignment has been effected, the free end of the flat cable 10 can be inserted through the entrance slot 24 into the slot 36 sufficiently so that the extremity of the cable abuts against the interior of the block 18, more specifically a portion of the wall forming the bore 25. When obstructive engagement is made with the block 18, the user knows that the cable 10 has been sufficiently inserted.

The next step is to rotate the cylinder 26. This can conveniently be accomplished by applying a suitable tool, such as a wrench, to the head 30. The rotation of the head 30 in a clockwise direction causes the cylinder 26 to be twisted or turned so as to draw into the annular space 38 a section of the cable 10. Sufficient rotation or turning from the position of FIG. 4 to the position depicted in FIG. 3 will cause some of the insulation material 12 into engagement with the teeth 42 formed on the contact elements 40. This results in the serrated contact elements 40 scraping or peeling a sufficient amount of the insulation 12 from the cable so as to establish electrical contact between the elements 40 and the ribbon conductors 14 that have up to this point been covered by the insulation 12. Outward deflection of the contact elements 40 is prevented because of the block 18 itself. Hence, the peeling of the insulation material 12 from the ribbon connectors 14 is a forceful and effective one. Consequently, an excellent electrical engagement is made and will be preserved as long as the cylinder 26 remains in the position it has been rotated into as illustrated in FIG. 3. It will be recognized that the thickness of the strip portions 41 and the teeth 42 thereon can be designed so that considerable pressure is applied to each ribbon conductor 14, if desired compressing the insulation 12 remaining between the conductors 14 and the cylinder 26.

As the rotation of the cylinder 26 progresses, it will be appreciated that the seal 56 is compressed somewhat and exerts a pressural action against the flat cable 10, continuing to do so even after the cylinder 26 has been rotated into the position in which it appears in FIG. 3. Rotation of the cylinder 26 causes the seal 60 to be angularly shifted and the seal 60 in this way acts against the side of the cable 10 lying substantially opposite the outer side against which the seal 56 bears. Hence, there is an excellent sealing action furnished which serves as a barrier against the entrance of moisture or deleterious substances to the region where the actual electrical contact is being made. Still further, the seal 54 prevents entrance of moisture of any contaminant-laden atmosphere in the opposite direction since the seal 54 bears against the cylinder 26, being somewhat larger in a radial direction than the seal 56. Consequently, a connector 16 constructed in accordance with the teachings of my invention may be used in virtually any environment.

Owing to the bending of the flat cable 10 from its straight line position as depicted in FIG. 4 when the position of FIG. 3 is reached, it will be recognized that the cable is firmly held or retained and that it cannot be inadvertently detached from the connector 16 by a tensile force applied to either the cable 10 or the connector 16 when not affixed to a support. Yet the release of the cable 10 can be easily accomplished by a reverse rotation of the cylinder 26. In this regard, the cylinder 26 can be rotated in a counterclockwise direction from the angular position in which it appears in FIG. 3 back to the initial position shown in FIG. 4, thereby allowing the cable 10 to be withdrawn without interference.

I claim:

1. A connector for engaging a flat cable having at least one ribbon conductor therein covered with insulation material. the connector comprising a block having an entrance slot for the insertion of one end of the flat cable, a cylindrical member rotatable within said block having a diametrically disposed slot therein registrable with said entrance slot, said cylindrical member having a cross section such that an annular space is formed between said cylindrical member and the interior of said block, and a contact element for each ribbon conductor extending into said annular space at a location spaced angularly from said entrance slot, each contact element having means thereon for removing some of said insulation material and engaging electrically said conductor.

2. A connector in accordance with claim 1 in which said insulation-removing means includes laterally spaced serrations.

3. A connector in accordance with claim 2 in which each contact element includes a strip portion extending generally tangentially into said annular space at said angularly spaced location, said serrations projecting radially inwardly from one side of said contact element toward said cylindrical member and the other side of each contact element abutting said block.

4. A connector in accordance with claim 3 in which said angularly spaced location is such that the serrated end of each contact is quadrantly located with respect to said entrance slot.

5. A connector in accordance with claim 4 in which said block includes a resilient seal projecting radially inwardly into said annular space, said seal being between said entrance slot and said contact element.

6. A connector in accordance with claim 5 including a second seal disposed on said cylindrical member and rotatable therewith into a position substantially opposite said first seal.

7. A connector in accordance with claim 6 including an additional seal on said block extending radially inwardly to said cylindrical member, said additional seal being located in an opposite angular direction from said first seal with respect to said entrance slot.

lOlOOl 0653 

1. A connector for engaging a flat cable having at least one ribbon conductor therein covered With insulation material, the connector comprising a block having an entrance slot for the insertion of one end of the flat cable, a cylindrical member rotatable within said block having a diametrically disposed slot therein registrable with said entrance slot, said cylindrical member having a cross section such that an annular space is formed between said cylindrical member and the interior of said block, and a contact element for each ribbon conductor extending into said annular space at a location spaced angularly from said entrance slot, each contact element having means thereon for removing some of said insulation material and engaging electrically said conductor.
 2. A connector in accordance with claim 1 in which said insulation-removing means includes laterally spaced serrations.
 3. A connector in accordance with claim 2 in which each contact element includes a strip portion extending generally tangentially into said annular space at said angularly spaced location, said serrations projecting radially inwardly from one side of said contact element toward said cylindrical member and the other side of each contact element abutting said block.
 4. A connector in accordance with claim 3 in which said angularly spaced location is such that the serrated end of each contact is quadrantly located with respect to said entrance slot.
 5. A connector in accordance with claim 4 in which said block includes a resilient seal projecting radially inwardly into said annular space, said seal being between said entrance slot and said contact element.
 6. A connector in accordance with claim 5 including a second seal disposed on said cylindrical member and rotatable therewith into a position substantially opposite said first seal.
 7. A connector in accordance with claim 6 including an additional seal on said block extending radially inwardly to said cylindrical member, said additional seal being located in an opposite angular direction from said first seal with respect to said entrance slot. 